Carrier-wave receiving system



'. Feb. 7, 1925. 1,526,408

F. W. YOUNG CARRIER WAVE RECEIVING SYSTEM Filed Aug. 24, 1921 2 Sheets-Sheet 1 //7 ew/0r fled W YOU/79,

ZQJW 41 5 Feb. 17. 925- 1,526,408

I F. w. YOUNG' CARRIER WAVE RECEIVING SYSTEM Filed Aug. 24, 1921 2 Sheets-Sheet 2 Patented Feb. 17, 1925.

UNITED STATES PATENT OFFICE.

FRED W. YOUNQ OF LONG ISLAND CITY, NEW YORK, ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK. V

CARRIER-WAVE RECEIVING SYSTEM.

Application filed August 24, 1921. Serial No. 495,054.

To aZZ whom it may concern:

Be it known that I, FRED W. YOUNG, a citizen of the United States, residing at Long Island City, in the county of Queens,

State of New York, have invented certain new and useful Improvements in Carrier- Wave Receiving Systems, of which the following is a full, clear, concise, and exact description.

This invention'relates to carrier wave receiving systems and more particularly to demodulatin circuits.

The principal object of the invention is to provide a circuit such that demodulators of differentkinds may be used without substantial change in the circuit itself.

A feature of the invention consists in providing a crystal or other rectifying demodulator with a base member adapted to lo cooperate with the socket member of a threeelement thermionic demodulator.

According to this invention, the receiving circuit is provided with a demodulator socket adapted to cooperate with the ordinary three-element" thermionic demodulator. When such a demodulating element is fitted into this socket, it will be properly connected to have the incoming energy appliedto its input circuit and to have cathode to heating current and space current supplied to the demodulating element itself. A demodulator of another type such as the wellknown crystal rectifier may be mounted on a base member adapted to cooperate with 8| this same socket. If because of failure of the thermionic detector or the associated sources of heating and space current it is desired to use the simpler demodulator, the thermionic demodulator may be removed and the rectifying demodulator substituted therefor.

The invention will best be understood by reference to the drawing in which Fig. 1 illustratesthe schematic diagram of a radio receiving system for receiving and demodulating high frequency waves; fFi 2, a crystal or other rectifying demo ulator; Fig. 3, the efiective circuit of Fig. 1 with the demodulator of Fig. 2; Fig. 4, a threeelement thermionic demodulator; Fig. 5, the effective circuit of Fig. 1 with the demodulator of' Fig. 4; Fig. 6, a radio receiving arrangement similar to Fig. 1, but

slightly modified; Fig. 7, a diagram of a rectifying demodulator; Fig. 8, the effective circuit when the demodulator of Fig. 7 is associated with the circuit of Fig. 6; Fig. 9, a three-element thermionic demodulator; Fig. 10, the effective circuit when the demodulator of Fig. 9 is used with the circuit arrangement of Fig. 6 and Figs. 11 and 12 show the base and socket of the demodulator of Fig. 7 in side and end elevation respectively. 1

Referring to Fig. 1, receiving antenna 1 is inductively connected by means of transformer 2 to a tuned circuit 3 including the secondary winding of the transformer 2 and a variable tuning condenser 4. A demodulator socket D of the well-known type used for the three-element thermionic demodulator is provided with terminals G, P, F and F The terminal G is connected to a terminal of condenser 4 through a stopping condenser 5 and the terminal F is directly connected to the other terminal of condenser 4.. An extremely high resistance R is shunted across the input terminals of device D. Connected to the output terminals P and F is the output circuit including in series source E and a receiver or other translating device 6. A two-way switch 7 permits source E to be cut out of the circuit if desired. Source E is connected in series with the regulating resistance 8 between the terminals F and F The demodulator socket D is provided with four contact strips, 9, p, f, and f which are directly connected electrically with terminals G, P, F and F respectively.

Fig. 2 shows a diagram of an ordina criystal or other two-element demodulator a apted to cooperate with the circuit of Fig. 1. This demodulating element has two active contact terminals, 9 and p, and two dummy contact terminals, f, and f adapted to contact respectively with the contact strips 7, and f, of element D. The insertion of the demodulator of Fig. 2 in thesocket member D of the Fig. 1 circuit produces eifectively the circuit arrangement of Fig. 3. In the arrangement high frequency oscillations received by antenna 1 are supplied to the circuit 3, tuned to the frequency of these oscillations, from which they are impressed through the condenser 5 upon the rectifying demodulator to yield low frequency waves in the 'circuit of receiver 6. If desired, switch 7 may be thrown to eliminate source E from the circuit, but this is in general unnecessary.

Fig. 4 illustrates diagrammatically a demodulator or the three-element thermionic known vacuum tube circuit commonly used in demodulating high frequency oscillations. As is well known, the base member of a thermionic demodulator is ordinarily pro vided with a bayonet pin in order to insure that the proper connections are made between the contacts of the demodulating device and the contactor strips of the socket. In the circuit arrangement of Fig. 6, the socket member D is provided with an extra contactor strip 10 which engages the bayonet pin and is directly connected to a point between the negative terminal of source E and translating device 6.

Fig. 7 shows adiagram of an ordinary crystal or other two-element demodulator adapted to cooperate with the circuit of Fig. 6. This demodulating element has twov active contact terminals, 9, and f, and a connection is also taken from terminal gr to the tip t of the bayonet pin 13. The insertion of the demodulatorof Fig. 7 in the socket D of the Fig. 6 circuit produces efl'ectively the circuit arrangement of Fig. 8. It may be noted that in this circuit arrangement the resistance element It is connected in shunt to the demodulating element, but its impedance is so extremely high that it has little or no efiect upon the response obtained in the receiver 6.

Fig. 9 shows a diagram similar to that of Fig. 4 of a thermionic demodulator adapted to cooperate with the socket D of the Fig. 6 circuit to produce elfectively the circuit arrangem'ent of Fig. 10.

Fig. 11 shows a detail of a portion of the demodulator of Fig. 7. In this arrangement, the socket member D is provided with a resilient contact member 10 insulated from the other contactor strips of the base and electrically. connected with the. negative terminal of the space current source. The base member 12 of the detecting element is provided with the usual bayonet pin 13 which cooperatesv with bayonet slot 14 as shown in Fig. 12. The bayonet pin carries a contacting tip t which is preferably electrically in sulated from the pin as a whole, but is directly connected to the contactor g, as indicated in Fig. 7.

hat is claimed is:

1. A demodulator element having a base and terminal contacts mounted thereon, a socket member having means for electrically engaging said contacts to complete circuits for said demodulator element, a projecting pin on said base member,'one of said terminal contacts being carried thereby, and a bayonet slot in said socket member cooperating with said projecting pin to lock said base in said socket member.

2. A demodulator element having a base and terminal contacts mounted thereon, a socket member having means for electrically engaging said contacts to complete circuits for said demodulator element, a projecting pin on said base member, one of said terminal contacts being carried thereby, and a bayonet slot in said socket member cooperating with said projecting pin to lock said base in said socketmember and a spring in front of said slot for making electricalconnection to said pin.

3. A radio receiving system comprising an antenna, an input circuit-coupled to said antenna, an output circuit including a -re ceiving device, means for interposing between said circuits a demodulating element comprising a base portion havingcontacts, one of said contacts projecting radially therefrom, said means comprising a socket having a tubular portion, a bayonet slot in said tubularportion and means for making electrical connection to said projecting pin when said element is inserted in said socket.

4. In a radio receiving system the combination with a socket of a demodulating device having a base and terminal contacts thereon, one of said contacts comprising a radially projecting pin, said socket comprising a base portion having an opening therein, a. tubular portion fitted in said opening and arising therefrom, a plurality of contact springs secured to but insulated from said base. said springs projecting under the base portion and beneath said opening and so disposed as to make connection with certain of the contacts on the said demodulating device in a prearranged manner and an additional contact spring arranged to make electrical connection with said radial projecting pin.

5. Means for associating a demodulating device, including a plurality of contacts,

with a radio-receiving system, which comprises a socket including a base portion and a tubular portion, a plurality of radially disposed contact springs in said base portion, arranged to make connection with certain contacts on said demodulating device and an additional contact spring extending vertically from said base portion for making 1. tact are located, aligned, positioned and designed to contact with terminals of a dif fcrent detector inserted into said socket whereby circuit elements including said socket may conveniently be used with different detectors.

In witness whereof, I hereunto subscribe my name this 6th day of August, A. D., 1921.

FRED W. YOUNG. 

